I always thought the Rival Battles in G/S/C/HG/SS were the easiest. For the reasons are that his movesets are god-awful and his Pokemon are patheticly under-leveled. In the last fight with him prior to the Elite 4, 3 of his Pokemon aren't fully-evovled, and if you count the National Pokedex, FIVE of his Pokemon aren't fully evovled. And if you started with Chikorita, ALL of his team isn't fully evovled when you fight him when you're liberating Radio Tower. It's really .